The invention claimed herein relates generally to loading dock bumper devices used to protect loading docks and/or vehicles from damage resulting during the loading/unloading process and, more particularly, to a vertically movable loading dock bumper device.
Loading dock bumper devices are well known in the art. They are used to protect loading docks and vehicles from damage resulting from the vehicles contacting the loading dock during loading and/or unloading activity. Damage to the loading dock and/or the vehicle would otherwise occur because a typical loading/unloading activity is initiated by the vehicle backing towards the loading dock until the rear of the vehicle is very close to the loading dock. Because too great a gap between the vehicle and the loading dock would make loading/unloading difficult, drivers typically err on the side of bringing the vehicle too close to the loading dock, often resulting in contact therewith. Having a loading dock bumper disposed between the vehicle and the loading dock allows the vehicle to back towards the loading dock without fear of contact, as the dock bumper disperses the force of a low speed contact without damage to either the vehicle or the loading dock.
Most loading dock bumper devices are immovably fixed to loading docks. Swessel, et al., U.S. Pat. No. 4,744,121 (May 17, 1988), discloses such immovably fixed dock bumpers. Other configurations use dock bumpers which are affixed to moveable portions of the loading dock, but in such configurations the bumper is essentially immovable once the loading dock has been correctly positioned for the specific vehicle and loading/unloading begins. Hahn, U.S. Pat. No. 6,360,394 (Mar. 26, 2002) discloses dock bumpers fixedly attached to a movable dock leveler, and van de Wiel, et al., U.S. Pat. No. 6,497,076 (Dec. 24, 2002) discloses a bumper affixed to a device which moves between an operative position and a stored position. However, in both these devices once the dock bumper is positioned for the loading/unloading activity, it remains in that position and effectively becomes an immovable bumper for the duration of the activity.
The disadvantage of such devices is evident from observations of their use with vehicles employing air suspension technology. The cargo box or trailer of a vehicle so equipped moves vertically on its air suspension mechanism to accommodate different cargo weights. A lighter load causes the cargo box or trailer to ride higher, and a heavier load causes it to ride lower. During the loading/unloading process, however, the weight of the cargo necessarily changes. Moreover, machines that may be used in the loading/unloading process, such as forklifts, can substantially (if only temporarily) alter the weight of the vehicle when they are driven onto and off of the vehicle. As a result, during the loading/unloading process the vehicle is often caused to move vertically, often in both directions and often with many movements, corresponding to the changing weight within the cargo box or trailer.
When a vehicle is backed against a dock bumper, lateral forces continue to be exerted against the bumper by the vehicle as long as contact continues. When a vehicle having an air suspension mechanism moves vertically during the loading/unloading process, as described above, the lateral forces against the bumper (or even friction between the rear of the vehicle and the bumper) may be sufficient to overcome any slipping between the rear of the vehicle and the bumper, the bumper is physically moved along with the vehicle. When such movements exceed the deforming properties of the bumper, the bumper is either ripped, torn, or otherwise damaged, or detached from the loading dock, or both.
A dock bumper device which permits the dock bumper to move in concert with the rear of the vehicle during the loading/unloading process significantly reduces the damage that would occur to the dock bumper and/or the loading dock, as described above. As such, replacement, repair, and maintenance of the dock bumper is greatly reduced, at significant cost and time savings.
Examples of vertically movable dock bumpers are disclosed in the following references:
Drawing xe2x80x9cAdjustable Bottom Pad (692-0029)xe2x80x9d; dated Oct. 17, 1985 (showing a vertically adjustable pad mounted to the dock face);
Spec Sheet xe2x80x9cLoading Systems Mobile Dock Bumper RB 250Mxe2x80x9d; dated circa 1993 (showing a vertically-adjustable spring-loaded dock bumper); and
Drawing xe2x80x9cHohenbeweglicher Anfahrpuffer 5146.0102xe2x80x9d; dated November 1995 (showing a vertically-adjustable, spring-loaded dock bumper).
While each of these references discloses a vertically movable dock bumper, the devices disclosed therein are of complicated and inferior design. As such, the cost of manufacture and/or installation of these devices would be high, as would be the likelihood of failure during operation. The invention claimed herein seeks to address these design flaws with its simple yet rugged design and utilization of a movement mechanism which reduces the potential for lateral binding present in the devices disclosed in the prior art, thereby resulting in a reduction of the deficiencies inherent in the prior art devices.
In one aspect, the invention is directed to a loading dock bumper device adapted to allow for the vertical movement of a bumper. This aspect may include one or more of the following features:
a mount component, a bumper component, and a slide component, whereby the mount component is suitably adapted to fixedly attach to a loading dock, the bumper component is suitably adapted to accommodate a bumper, and the slide component is suitably adapted to connect the bumper component to the mount component in a manner permitting the bumper component to move along the mount component in a vertical direction in concert with the vertical movement of a vehicle; the mount component may be constructed of channel iron having a substantially flat back panel and two lateral flanges, a top plate constructed of sheet steel or bar stock, and an attachment plate constructed of angle iron; the bumper component may be constructed of channel iron having a substantially flat front panel and two flanges oriented along the top and bottom, with the bumper component suitably adapted to fit within the flanges of the mounting component and against the inner surface thereof, and suitably adapted to carry a bumper on its outer surface; and the slide component may be constructed of a pair of steel rods with a pair of springs disposed thereon, with the pair of rods disposed through apertures formed into the mount component and the bumper component such that the rods are fixedly attached to the mount component and retain the bumper component within the mount component, and the springs support the bumper component and facilitate its movement in a vertical direction.
Other features and advantages of the invention are described below.